Grinding and polishing head



Dec. 13, 1955 Filed Dec.

A. VEGELL GRINDING AND POLISHING HEAD NLn WEC-

2 Sheets-Sheet 1 VMMSL mvENToR ALLEN Veer-:LL

ATTO R EW Dec. 13, 1955 A. VEGELL GRINDING AND POLISHING HEAD 2 Sheets-Sheet 2 Filed Dec. 19, 1950 ATTORNEYS United States Patent O GRINDIN G AND PLISHING HEAD Allan Vegell, Elmhurst, Ill., assignor to Standard Process Corporation, Chicago, Ill., a corporation of Delaware This invention relates to grinding or abrading mechanisms and in particular to a grinder head that can be selectively used for relatively coarse grinding or for polishing.

In the preparation of printing cylinders and plates, as for example rotogravure and textile cylinders, the cylinder or base is ground to size and then polished to a mirror-like finish. The grinting Wheel is normally quite hard to remove metal relatively rapidly, and during the grinding operation it is preferable that the wheel be iixedly positioned relative to the work, so that accurate dimensions can be obtained. During polishing and finishing operations the dimensions of the work are not substantially changed, the wheel itself may be relatively soft, and it is generally desirable toyieldingly hold the polishing wheel against the work with a predetermined resilient force to control the pressure of the wheel against the work in accordance with the surface being treated and the finish desired. l

The wheel, whether a grinding or polishing wheel is mounted for rotation in ahead which is adjustable tomove the wheel toward or away from the work, to drive the wheel at selected speedsifor grinding and polishing, and which may provide for an oscillatory motion of the wheel with respect to the work. In the head shown in the accompanying drawings as an illustrative embodiment of my invention, a planetary two speed transmission proviles a combined rotary and oscillatory drive for the wheel at one speed and another simple rotary drive at a second speed during which there is a non-oscillatory adjustable resilient pressure drive. During the combined oscillatory and rotary drive the grinding wheel rotates about an axis which travels through a circular path, while the axis remains fixed during the simple rotary drive. While the illustrated embodiment shows a planetary gear drive that will provide slightly different wheel speeds during oscillatory and non-oscillatory rotation, this difference is relatively unimportant because the wheel speed is primarily controlled by the motor drive, usually a multispeed motor. Either, grinding or polishing may be accomplished with oscillating or non-oscillating rotation of the wheel, and at any desired selected speed.

While it is preferable that the wheel be xedly positioned relative to the work during grinding it is to be understood that there may be occasions when a floating or resilient positioning may be desirable. My improved head provides selectively a fixed position or a resiliently floating position of the wheel with respect to the work, either of which positions may be used either for grinding or for polishing.

It is therefore a primary object of my invention to provide a novel head for grinding and polishing operations wherein a simple adjustment is effective to convert the drive from a rigid adjusted arrangement to an adjustable resilient arrangement.

Another important objectof my invention is to provide l.

a new and improved driving head for a grinder and pol- 2,726,492 Patented Dec. 13, 1955 isher wherein a selection of speeds and yielding or positive oscillatory and non-oscillatory drives are obtainable.

A further object is the provision of an adjustable spring tensioning means for the grinder or polisher spindle.

Still another object is the provision of a mechanism for regulating the movement of the spindle from a resilient or floating to a positive drive position, for grinding or polishing.

It is another object to provide a new and improved planetary gear carrier.

Other objects will become apparent as the description proceeds in connection with the accompanying drawings and from the scope of the appended claims.

Figure l is a vertical sectional view through the head in a plane passing through the spindle axis when the spindle is vertical.

Figure 2 to 7 are detailed views of several elements of the head.

Referring to Fig. l my improved head comprises a tubular housing 11 having suitably affixed to its upper end an upper or gear housing 12. Protruding from the left side of housing 11 is vertical tubular boss 13 that contains bushings 14 and 15 which are internally threaded to receive threaded member 16. Bushing 14 is fixed within sleeve 17 rotatable within the bore of boss 13 to raise and lower housing 11 with respect to threaded member 16. Lower threaded bushing 1S is rotatable by member 18 to act as a lock-nut. Any other suitable adjusting mechanism may be used to adjust head housing 11 axially with respect to the main machine frame which in the present instance is represented by the xed threaded member 16.

Housings 11 and 12 journal driving or input shaft 19 and spindle 20 for a grinding or polishing wheel indicated at 21. Input shaft 19 is journaled in upper housing 12 by a ball bearing assembly 24 secured by clamping ring 25 and bolts 26 against annular boss 27 integral with upper housing 12. Sun gear 23 is secured to the bottom of input shaft by key 29, screw 32, and washer 33 which clamp the sun gear against the inner race of ball bearing assembly 24. Seal 34 around input shaft adjacent the top of gear housing 12 prevents entrance of dirt etc. into the housing. The protruding end of input shaft 19 has keyway 35 for driving engagement with the power source, not shown. Oil hole 36 provides for lubrication.

Clamping ring 25 also clamps the inner races of ball bearing assemblies 37 and 3S against external shoulder 41 on boss 27. Ring gear 42 is mounted upon the outer races of bearing assemblies 37 and 38 which are clamped between internal shoulder 43 on ring gear and a shoulder on clamping ring 44 that is secured to ring gear as by screws 45. Ring gear 42 is thus securely mounted for rotation within gear housing 12.

A pair of coaxial elements 46 and 47 are rigidly secured together as by screws 48 to form a hollow spindle within tubular housing 11. Brake drum 51, having substantially the same outer diameter as the cylindrical external surface of ring gear 42, is secured by threads 52 to the upper end of element 46 and a set screw 65 locks element 46 and brake drum 51 against unthreading. Brake drum 51 clamps the inner race of ball bearing assembly 53 against a shoulder on element 46, the bearing assembly 53 journallng the upper end of the hollow spindle for rotation, as will become apparent. The outer race of bearing assembly 53 is pressed upwardly by a ring 54 which engages it and which has an outwardly extending tiange 56 pressed upwardly by a series of springs 55 seated in vertical holes encircling the upper end portion of tubular housing 11. This construction preloads the bearing assembly 53, and if the springs 55 become sufficiently compressed flange 56 will rest directly upon the upper end of tubular housing 1"1.

As will be apparent from Figure 1, ball bearing assemblies 57 and 58 are received in the bore of the hollow spindle adjacent the juncture of spindle elements 46 and 47, and this bore and the axis of bearing assemblies 57 and 58 is slightly offset from, and not coaxial with the axis of the input shaft 19, although the axis of bearing assembly 53 is coaxial with that of the input shaft.

A planetary gear carrier designated generally by the reference number 61, comprising an integral structure of two spaced upper and lower plates 62 and 63 respectively, connected by three equiangularly spaced ribs 64 (only one of which is shown) is secured to the top of the hollow spindle assembly and brake drum 51 by four cap screws (not shown) which pass through the lower plate 63 and are threaded into the top of the hollow spindle-brake drum assembly. A planetary gear supporting shaft 66 is mounted at its ends in spaced plates 62 and 63 and supports a pair of spaced bearing assemblies 67 and 68 separated by spacer bushing 71. The bearing assemblies 67 and 68 rmly support for rotation within carrier 61 a planetary gear having upper and lower sets of teeth 72 and 73, which mesh respectively with sun gear 28 and with output gear 74 coaxial with bearing assemblies 57 and 58 which are offset from the axis of input shaft 19.

The hollow spindle dened by the elements 46 and 47, supported at its upper end by bearing assembly 53 is supported at its lower end by element 47 which has threaded section 76 onto which is threaded clamping nut 77 to hold inner race of bearing assembly 78 against shoulder 79 on member 47. Bearing retaining ring 81 has an upper' inner shoulder 80 that receives outer race of bearing assembly 78. Ring 81 also has lower outer shoulder 82 that seats against the lower end of tubular housing 11. @taining ring 81 is secured in place by clamping ring 83 held by a series of screws 84 threaded into tubular housing 11, and has concentric annular surfaces bearing against the lower end of housing 11 and against the outer race of bearing assembly 78. Thus there is provided a secure rotary bearing support for the lower end of element 47 of the hollow spindle formed by elements 46 and 47.

Internal hollow spindle 85 is journalled adjacent its upper end in elements 46 and 47 forming the first hollow spindle, being seated within the inner races of the bearing assemblies 57 and 58. Adjacent its lower end the internal hollow spindle 85 is seated in the inner races of bearing assemblies 86 and 87, the outer races of which are clamped against shoulder 88 in member 47 by externally threaded ring 91A within element 47, and spacing bushing 92. A set screw 91B locks ring 91A in position.

Output gear 74 ts within internal hollow spindle 85 adjacent the top thereof, and is keyed thereto by key 93. Downward movement of output gear 74 is prevented by ring 94 and sleeve 95 resting upon the top of the inner race of bearing assembly 57 and has a clearance within the central bore of element 46. Seal 96 surrounding ring 94 prevents entrance of dirt or the like into said clearance. Hollow bushing 97 tits within the bore of output gear 74 and against internal shoulder 98 in the hollow spindle 85, being xedly secured thereto by means such as a tapered plug 99 or the like, shown as a circular dotted line in Fig. l. At its upper end bushing 97 is pulled up within output gear 74 by nut 102 seated upon an internal shoulder near the top of output gear 74. A direct drive is thus provided between output gear 74 and internal hollow spindle 85 journalled within the hollow spindle formed by elements 46 and 47, and hollow bushing 97 rotates with internal hollow spindle 85. The inner races of bearing assemblies 57 and 58 are clamped against the bottom of sleeve 95 by means of flanged ring 90 and split ring 89 (diametrical split not shown) seated partially within flanged ring 90 and peripheral groove in internal hollow spindle 85.

The grinding tool spindle 20, upon the lower end of which is secured grinding or polishing head 21, has an axially sliding tit within the bore of internal hollow spindle 85. However, its upward movement is limited by frusto-conical section 103 adjacent its bottom end, which seats against mating recess 104 at the bottom end of spindle S5. In Figure 1, frusto-conical section 103 is shown seated against mating recess 104, so that spindle 20 is at the upper limit of its axially sliding movement. lts upper end is spaced slightly below the lower end of hollow bushing 97, and has an axial bore 105 substantially the same diameter as bore 106 within the bore bushing 97 axially aligned therewith.

Bore 105 in spindle 20 receives element 107 also shown in detail in Fig. 2. Element 107 has cylindrical section 108 with diametrical through slot 109 rounded at its top and bottom, and which snugly receives a transversely extending plate 112 shown in side elevation in Fig. l, and in end elevation in Fig. 3. Plate 112 protrudes equidistantly from the sides of the spindle 20 and extends through diametrically opposed slots 113 and 114 (Fig. l) in hollow spindle 85, slots 113 and 114 being longer vertically than plate 112 which can slide vertically in the slots 113 and 114 while being held snugly in position normal to spindle 20 by its tit within the slot 109 in element 107.

At its upper end element 107 has threaded section 115 (Fig. 2) onto which are threaded coils of a spring 116 (Fig. 1), the lower end of which abuts a radial shoulder 117 (Fig. 2) on element 107. The upper end of spring 116 is threaded onto element 118 (Fig. 1) which is also internally axially threaded to receive the lower threaded end of bolt 121, the head of which is held against a shoulder in the upper end of the hollow bushing 97 by screw plug 122. The initial compression of spring 116 (when the spindle 20 is in its uppermost position as in Fig. 1) is controlled by adjusting the axial position of bolt 121 in element 118 and then pushing the bolt head against its seat in the upper end of hollow bushing 97 and locking it there by means of screw plug 122. Thus in this position compression spring 116 resiliently urges spindle 20 downwardly and away from its seat at 103-104, but such movement is prevented by the seating of clamping collar 137 in the bottom of an annular recess 138 as will be apparent.

The absolute limit of the downward movement of spindle 20 is determined by the bottom of slots 113 and 114 in spindle 85, but actually the spring 116 will be tensioned to support the spindle 20 before plate 112 bottoms in these slots, as will be explained. Preferably, the bottoms of these slots are rounded as is the bottom of slot 109 in the element 107 (Fig. 2). Externally threaded split ring 123 is seated in a turned groove in the outer surface of spindle 85 and held from turning by two square head pins or keys 124 Whose heads mate into keyways in split ring 123. Collar 125 tted around spindle 85 has internal threads engaging the threaded ring 123 and collar 125 is turned so as to clamp ring 91 against spacing bushing 92A to clamp the inner races of bearing assemblies S6 and 87 against shoulder 88. Once so positioned set screw 126 or the like is used to lock collar 125 in position.

Collar 125 is also externally threaded to engage an internally threaded hollow cylindrical element 127 secured as by screws 128 to annular element 131 having bevel gear teeth 132 on its upper surface for engagement by bevel gear teeth 133 on a T handled adjusting tool 134 shown in Figure 4, that is insertable through an opening (not shown) in the tubular housing 11. Turning of the elements 127 and 131 by tool 134 raises or lowers them because of the threaded engagement of element 127 with collar 125. The internally threaded surface of element 127 has a number of equiangularly spaced vertical V shaped grooves, one of which is shown at 135 in Figure 1. Spring pressed ball 136 within collar 125 seats within any one of grooves 135 to lock the connected elements 5 127-131 in any adjusted position when a groove 135 is aligned with ball 136. In any event the elements 127- 131 cannot rotate because of vibration or the like farther than the angle between any two adjacent grooves 135. Clamping collar 137 (see also Figs. 5, 6 and 7) is rotatably seated within annular recess 138 in the top of element 131 and is also vertically slidable therein. AS best shown in Figs. 5, 6 and 7, collar 137 has a diametrically extending slot 141 within which are snugly embraced those portions of plate 112 that protrude outwardly beyond the internal hollow spindle 85. Clamping screws 142 and 143 extend through slot 141 and through holes in opposite protruding ends of plate 112 to rigidly secure plate 112 to collar 137. The inner end of adjusting tool 134 is inserted into a radial hole 139 in a hardened bushing 140 in collar 137 when adjustments of the spindle 20 are being made. By this construction, if the connected elements 131-127 are lowered by means of tool 134 of Fig. 4 spring 116 will press spindle 20 downwardly and maintain collar 137 seated within recess 138 in member 131. However, an upward force on wheel 21 suiicient to overcome the force of spring 116 can push spindle 20 upwardly towards its seat at 103-104. The spring 116 is of such length that if elements 127-131 are lowered sutliciently the spring will support the tool spindle 20 by tension in the spring. In such event the clamping collar 137 will be disengaged from its seat in the annular recess 138. The spindle 20 will then be floating, in the sense that it will be supported solely by the tensioned spring 116. Pressure of the grinding or polishing wheel 21 against the work is then controlled by raising or lowering the entire head by means of the threaded member 16.

Thus a grinding or polishing head is provided that will furnish a solid position for the wheel 21 when desired, by reason of the seat at 103-104. However, 127-131 may be lowered to allow spring 116 to pushA the spindle 20 downwardly so that the wheel 21 will be urged against the work piece by the force of the spring 116 and this force is adjustable from zero to a maximum by adjusting the position of the entire head. In order to change from a pure rotary to combined rotary and oscillatory operation the grinding-polishing head assembly should first be moved away from the work by means of the adjusting means shown on the left side of the housing 11 in Fig. 1.

During combined rotary and oscillatory operation, ring gear 42 is held stationary by means of brake band 145, and the wheel 21 will be driven at one speed and will have a circular oscillatory motion of its axis by reason of rotation of elements 46 and 47, because a second brake band 146 will not be holding brake drum 51 against rotation. When lower drum 51 is held stationary by the brake band 146 wheel 21 will be driven at a slightly different rotary speed but its axis will be fixed. Upper brake band 145 releases the ring gear 42 during rotary non-oscillatory motion.

The control for selectively actuating brake band 145 or 146 comprises shaft 147 rotatable by means of a handle to either of two positions. Any conventional means may be used in connection with rotatable shaft 147 -to selectively actuate the brake bands 145 or 146.

It is to be understood that if desired, either grinding or polishing may be done whether the wheel 21 is positioned positively by means of the seat at 103-104 or whether 103--104 is unseated. In the latter case the pressure of the grinding or polishingwheel 21 against the work can be adjusted from zero (when the spindle 20 is supported by the spring 116 in tension) to any desired maximum figure, by adjustment of the spring with the tool 134 and of the vertical position of the head by the threaded member 16.

Lubrication of the rotating parts is provided by oil hole 36 and by alemite grease ttings 149, 150 and 151. Oil hole 152 in the output gear 74 and an aligned hole 153 in the sleeve 95 also provide lubrication. Seals 155 and 156 prevent the entrance of dirt into the bearing 6 assemblies 86 and 87, and there is another seal at 158 below the lowermost bearing assembly 78. l

The details of the mounting of the grinding or polishing wheel 21 upon the lower end of the spindle 20 do not form any part of this invention. As shown in Fig. 1

` wheel 21 is suitably secured to a holder 160 which in turn is mounted on tapered lower end of spindle 20, being rigidly held thereon by a tapered through pin 161 which is accessible only when the spindle 20 is lowered.

The invention maybe embodied in other specic forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended' claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What isclaimed and desired to be secured by United States Letters Patent is:

l. In a grinding and polishing machine, a housing; a first hollow spindle mounted for rotation within said housing; a second hollow spindle mounted for rotation within said first rhollow spindle but about a spaced parallel axis; a third spindle rotatably and axially slidably mounted coaxially within said second spindle; a planetary gear carrier secured to said first hollow spindle; a planetary gear journalled on said carrier; a gear driven by said planetary gear and connected to drive said second hollow -spindle whereby said first and second hollow spindles may be driven ywith respect to each other about spaced axes by said planetary gear; connecting means operable to drive said third spnidle from said second spindle; resilient means urging said third spindle axially in either direction; means adjustably positionable on said second spindle for controlling the amount and direction of the force exerted by said resilient means; fixed means limiting the axial movement of said third spindle in one direction; and adjustable mean-s limiting the axial movement of said third spindle in the opposite direction.

2. In combination, a housing; an abrading wheel spindle rotatably and axially slidably mounted on said housing for rotation about a vertical axis; means for rotating said spindle including a connection operable to rotate said spindle irrespective of its axial position with respect to -said housing; means operable to positively limit the axial movement of the spindle in an upward direction; spring means operable to resiliently oppose the movement of the spindle in said lupward direction and so connected t0 the spindle as to resiliently support the entire weight of the spindle and abrading wheel and other parts carried thereby; and means operable to adjust the vertical position of 3. In combination, a housing; an abrading wheel spindle rotatably and axially slidably mounted on said housing for rotation about a vertical axis; means for rotating said spindle including a connection operable to rotate said spindle irrespective of its axial position relative to said housing; means operable to positively limit the axial movement of the spindle in one direction; spring means operable to resiliently oppose the movement of the spindle in either direction and so connected to the spindle as to resiliently support the entire weight of the spindle, including the abrading wheel and other parts carried thereby; and means operable to adjust the vertical position of said housing, whereby the abrading wheel carried by the spindle may be positioned to contact the work piece to be abraded with pressures ranging from zero to a predetermined maximum.

4. In combination, a housing; an abrading wheel spindle rotatably and axially slidably mounted on said housing for rotation about a vertical axis; means for rotating the spindle including a connection operable -to rotate the spindie irrespective of its axial position ,relative .to said housing; `means voperable-,to positively limit the axial movement -of the spindle in one direction with respect lto said hous'- ing; means operable ,to Vresiliently oppose the movement of the spindle in either direction `and so `connected to the Aspindle as to resiliently `support the entire weight of the spindle, including the abrading wheel and other parts carried -by the spindle; and means `operable to adjust the relative vertical positions of said spindle and said housing, whereby the abrading wheel carried by the spindle may be positioned to contact `the wor-k piece to be abraded with pressures ranging from zero to a predetermined maximum.

5. In combination, means forming a housing; an abrading wheel spindle; means mounting said Aabrading wheel spindle `for rotation and axial `movement with respect to said housing; means for rotating said abrading wheel-spindie on its axis; a second spindle surrounding said abrading wheel spindle and mounted with respect to said housing so as to be rotatable with said abrading wheel spindle ,and axially fixed with respect `to said housing; force exerting means connected to said abrading wheel spindle for urging said abrading wheel spindle axially ina iirst direction; at least one axially extending radial slot in said second spindle to provide an axial abutment; means protruding radially from `said abrading wheel spindle into said radial slot to engage said abutment to limit the axial movement of said abrading wheel spindle in on'e direction with respect to said second spindle Vand housing under the influence of said force exerting means; means limiting the axial movement of said Aabradingwheel spindle in the opposite direction; and a collar surrounding said abrading wheel spindle and means Afor adjusting the axial position of said collar with respect to the abutment at one end of said axially extending radial slot in said second spindle to limit the range of positions of said abrading wheel spindle from a maximum range equal to the axial length of said slot, to a minimum range that prevents the axial movement of said abrading wheel spindle in either direction with respect to said housing.

6. In the device described in claim 5; means for rotating said abrading wheel spindle about a second axis spaced from but parallel to its own axis at the same time that it is rotated on its own axis.

References Cited in the le of this patent .UNITED STATES PATENTS 

